Systems Approach"

INTRODUCTION TO "SYSTEMS APPROACH" Gernot M. R. Winkler U.S. Naval Observatory Washington, D.C. DEFINITION AND OVERVIEW Systems and timekeeping have several "interfaces": First, all systems are subject to processes, or better, processes are the essential aspect of systems. I11 all these processes, time is the one general, abstract parameter which relates the state of these processes to the state of all other systems. Time is. therefore, the universal system parameter (I). Second, since time is the universal system interface, the use of clocks in systems is increasing, commensurate with our increasing demands for precision in systems interfacing. We now distin- guish a class of "time ardered systems" (even though in principle all systems are time ordered) in order to emphasize the precision aspects which necessitate the use of precision clocks (2). Third, all clocks are of necessity systems; systems in which we attempt to repeat the same processes as identically as possible so that we obtain a uniform time scale. Therefore, any system could be used as a clock, albeit, not a very good one, e.g. we ourselves are systems, i.e. clocks, and one can read the time off our faces! For these reasons, since clocks are systems, and are part of systems, a general overlook and introduction to the systems approach has been suggested. This appears the more appropriate since some of it, the most critical aspects of the subject, fall somewliat outside the purely engineering frame of mind; the subject is indeed trans-disciplinary. Onc may even be tempted to clai~vthat these most general, but strategically essential aspects of slstems belong to philosopily in its prope sense rather than to any specific technical specialty (3). Exhibit A attempts to sketch the scope of what is known today under various names such as cybernetics or General Systems Theory (GST). both meafiing more or less the same (4). What is a System? A system is a group of interacting elements or subsystems which is organized for a purpose. This purpose is clearly external or imposed in the case of artificial or synthetic systems. In natural systems, the purpose is inherent as a heuristic principle (5). The capabilities of a system are oftr. clearly reducible to those of its elements; this is the rule for technological systems of up to rathe remarkable sizes and complexities. However, very complex systems (lo8 is a most superficial di- viding mark for inter-acting elements) begin to show aspects which are qualitatively new and in principle irreducible to the qualities of the elements (6). This is partly due to the synergistic interaction of the subsystems and partly due to principle lim- itations of our intellect. Any intellectual process as we know it is inherently an abstracting proc ess with an incredible and unaccounted amount of data compression at every one of its many stages. Even our sensory perceptions are the eventual results of a most radical selection from the flood of primitive "inputs". In the complex systems environment, however, these ignored, or be ter, unknown aspects of the systems elements inevitably come to the fore and play unexpected roles. Then we are awakened to the fact that nature is (at least for us which are its "subsystems inexhaustible (7). Such ignored parts must appear to us as an irrational part which is irreducible (see Exhibit B #5). This, then, is the origin of "emergent" qualities 8). In our aijyiication here, where we consider systems of clocks, the question will, therefore, hate to be: What are the emergent qualities of clock systems? We may only hint at this point that one of them is the class of advantages of having a co-ordinated system of clocks with benefits obtained for each user while contributions are made to the timing community as a whole (9). SYSTEMS, A SUBJECT FOR THE ENGINEERING INTELLECTUAL: A most important decision at the beginning of any system consideration is to define the level of abstraction at which the system is to be treated. One will hesitate between the "Scylla" of ele- gant oversimplification and the "Charybdis" of unmanageable complexity and confusion. One may remember, though, that as a typical scientist, one may be wont to miss the forest because of the many interesting trees and also, that the real purpose of any system approach is in fact a view and an assessment of the forest. But, if we are to lean towards data economy, then we niust compensate this paucity with the quality of our concepts. What we wish to stress is that ingenious intuition i3 really indispensible for the discovery and the judgment of the intellectual tools to be used. i.e. the strategies. goals, concepts and hypotheses. Now inge~uityis something which can't be directed to appear on time. One has to invite it, but the humble waiting for the illuminating insight is worth almost any risk because the truly ingenious concept is literally invaluable (10). Competent nianagement (in its usual context) is a necessary, but for systems work, not yet suf- ficient condition. As we hinted before, it is the undocumented, even subconscious experience on which much ultimate systems performance will depend (1 1). One must therefore suggest that the lack of direct, intimatc, personal bench experience of many systems engineers is in the long run very, very expensive. The two reasons for this are: the need for an environment conducive to create thought and in- vention, and the need to train judgment and intimate experience. These should make it impera- tive to start with pilot projects, let people "fiddle around" a little, beforc serious consequential steps such as specifications writing can be taken. One can sense at this point that a certain generosity, a largc fiame of mind, 15 a desirable systems qualification - but how could one bring anyone to a deliberate expansion of the soul? (Without inflation, of course!) Now, in going back to the level of abstraction. we have here in these few minutes, no choice but to go for the pinnacle: Exhibit B can of necessity only be a lofty sketch, and I niay be forgiven for putting forth such conjectures as verities, alrliost as if thcy could be proved by my affirming them on oath. But. these are serious matters and thcy reprcscnt some of the basic things one finds as a resuit of great complexity. Sonic of Euliibit B is purely metaphysical such as tf7 (which was already mentioned by Lao-tsu (12)), but some are quite plausibly related to more basic ideas: Item #6 on the list is important because "systemic" measures are disastrous. But, it is also important to understand why that must be so. They are disastrous because they prevent the systeni trorn cvc.ltually correcting the real cause of the disturbance. The internal dynamics is being d~stortedby systcniic measures in the very direction which makes thc system's state cver more precarious: it i.; the direction leading into a sudden. catastrophic system collapse (1 3). They are most interesting because the study of the effects of systemic nieasures also gives insights into the connections between GST and "infornution", correct information and not "noise". We niirst also include in the importance of information the willingness to use it. This, however, is of.en prevented by preconceived notions or "policy". The example of economic systems and their inflations is notorious (14). Such ii hypothetical system of IOU subsystems, each interacting with (let us assume) lo4 others is a system of great complexity. We may take as a coarse meas- ure thc number ot possible interactions per unit time, e.g. , Let us now only sketch a fcw niore points which, while they are obvious. are obviously not being acknowledged easily: THE EXISTENTIAL LEAP IN THE DARK Whatever we do. we are forced to act ill ignorance of the total consequences of our ac. - life is a leap in the dark. In systenis design. however. we are not totally ignorant. We ha1 !~le specifications and user experience with available rnodules as "shelf iterns" for building r But, the crucial point is this: If we start from overall systems specifications, we will fin, ,,LZII many of these shelf items won't do the job. In order to stay within specifications we muit cus- torn design, build. test, debug. evaluate, change and produce rnany of our modules from scratch. (An item is not mature before several hundred have bcen opcrated in a systeni environment and the problems fed back to the debugging process). This. however. is a very expensive enterprise where one's resources may quickly disappear in guerrilla warfare with Murphy's Law (1 6). The lesson is thai very successful systenis must riot come into existence via the "grand scheme" with detailed dream-specifications. One rather has to start small (pilot projectj and one should difine only general system goals (17). But, one can require that all subsystems (modules) bc items which have been in production and used sufficiently long to bring cut and correct all their hidden problems. Such an approach does require a greater resourcefulness from your team. but you induce the ap- plication of brain power at the critical start of the project rather than for problem solving in the middle (when you hoped to be at the end). This way you don't have to lcap in conipletedarkness. Another point is more subtle so let us invokc an appropriately exotic cxample: THE SIAMESE CAT Let us consider the procurement of such a "systeni". Unfortunately. we cannot order it ar?ymore as it used to be done: "One cat (Siamese) each .

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